Multiflame welding apparatus



Jan. 28, 1947. H. T. HERBST NULTIFLAME WELDING APPARATUS Filed Aug. 2', 1940 HARRY t HERBST INVENTOR ATTORNEY Patented Jan. 28, 1947A http MULTIFLAME WELDING APPARATUS r Harry T. Herbst, Elizabeth, N. d., assigner to Union Carbide and Carbon Corporation, a corporation of New York Application August 2, 1940, Serial No. 349,393

'I Claims. l

This invention relates to welding apparatus and more particularly to an improved multia forming bell or between shaping rolls. In this operation, the heated skelp is formed into a tubular shape and its opposite longitudinal edges are brought together. Simultaneously with the pipe forming operation, the longitudinal edges of the skelp are weld united to complete the pipe.

In tube welding, the skelp is formed, while cold, into a tubular shape in a separate operation. 'The longitudinal edges of the formed skelp are later weld united to complete the tubing.

In both pipe and tube welding, when the Welding is done by the oxy-fuel gas process, a series of preheating flames or jets are directed upon at least the longitudinal edges of the skelp, and are followed by a series of welding flames or jets which weld unite the skelp edges as the' skelp enters the closing die or closing pressure rolls. The preferred type of welding flame is a low velocity, i. e., 250300' per second neutral flame' supplied with substantially equal volumes of oxygen and fuel gas. For various reasons, both series of arnes or jets are usually'provided by one welding head supplied with a gaseous .heating mixture from a single blowpipe. Consequently, the type of preheating flame heretofore used has also been a low velocity neutral flame. This type of iiame, however, when employed to preheat the work, is unstable and requires much auxiliary apparatus, such as air jets, to improve its stability and effect a more uniform heating. As the rate of heat transfer of this type of preheating flame is low, the speed of the operation is consequently decreased to a substantial extent. l

It is therefore an object of this invention to yprovide apparatus wherein both the speed and efficiency of the weldingoperation are. substantially increased without lmpairing the uniformity and qualityof the finished weld. Other objects are to provide a unitary multi-flame Welding head formed with means for producing one or more high velocity ames or jets and one or more low velocity flames or jets; to provide such a welding head in which both sets of flames or jets .are supplied with a gaseous heating mixture from a single blowpipe; to provide pipe and 2 tube welding means in which the necessity for auxiliary flame stabilizing means is eliminated; and to provide a unitary multi-flame welding head which is simple in constructionv and eflicientn operation.

These and other objects of the invention will in part be obvious and 4in part become apparent from the following description and the accompanying drawing, in which:

Fig. l is a diagrammatic view illustrating the principles of the method of the invention; and

Figs. 2 and 3 are longitudinal sectional views of two types of multi-flame welding heads em bodying the invention and adapted to perform the welding method oi the invention.

Generally speaking, in practicing the method of the invention, the work is progressively preheated by a series of relatively high velocity pra heating flames or jets directed.V upon the work. The welding is accomplished by directing a series of relatively low velocity welding flames or jets on the skelp edges just before the skelp enters the closing die or closing pressure rolls. .Both series of jets are preferably provided yby a single unitary welding head.

In one type of welding head embodying the invention, the gaseous heating mixture for both the preheating and welding flames or jets is pro vided from a single blowpipe connected to a unitary multi-name welding head. Means are provided in the welding head to reduce the pressure, and hence the velocity, of the `gaseous heat lng mixture provided for the welding flames or jets. In another type 0f welding head embodying the invention, each series of jets is provided with a gaseous heating mixture from a separate blowpipe and both blowpipes are connected to a single unitary multi-flame welding head.

Referring more particularly to the drawing, Fig. l illustrates the invention as applied to pipe and tube welding, in which a multi-flame Weld ing head H is shown as arranged in operative relation to the Work, such as formed skelp T. The skelp T moves'in the direction of the arrow, and as the skelp edges E pass beneath head H, the latter successively directs a series of high velocity preheating flames P and a series of low velocity welding flames W upon the skelp edges. Immediately after the formed skelp passes beneath the welding flames 'W, it passes through the closing die or closing pressure rolls (not shown) wherein the melted skelp edges E are forced together to form a fusion welded seam S.

The high velocity preheatin'g flames rapidly heat the skelp edges to a high temperature, and

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' 3 the low velocity welding ames complete the fusion of the edges, whereby the edges may be forced together'to form the seam S.

Both the preheating and the welding flames are supplied with a combustible mixture from a trated in'Fig. 2 comprises a shell IIJ drilled longitudinally to form a gas inlet chamber I2 and aligned gas outlet chambers I4 and I8 which are separated byvan integral partition or baille I8.

- The upper wall Illa of shell I0 is formed with a threaded inlet portion for connection with a blowpipe 22 or equivalent gas mixing device.

' The bottom thicker wall IIlb of shell I is formed with a longitudinally dispose-d series -of parallel municating with chamber I4, and a series of parallel welding -gas discharge ports or oriiices 26. communicating with chamber I6. A plug 26 permanently closes one end of chamber I2, and plugs 30 and 32-permanently close the outer ends of chambers I4 and I6, respectively. j

One endI of chamber lI2 is enlarged and threaded, as at 34, and pressure reducing means, such as an apertured threaded plug, or restricting orice, 36 is secured in the threaded portion ofthe chamber I2. The pressure reducing means 36, which is formedwith a kerf or socket 38 to permit its ready removal, divides thechamber I2 into high pressure and low pressure sections 40 and 42, respectively. The outer end of section 42 is` closed by a threaded plug 44. Cross.

drillings 46 and 48, through the wall 454 which separates chamber I2 from chambers I4 and I6, provide communication between section 40 and chamber I4 and between section 42 and chamber y I6, respectively. To distribute the gas uniformly .to the groups of outlets, the drilling 48 is located about centrally relatively to the orifices 26 and the drillings 46 are suitably spaced apart.

. The gaseous heating mixture from the gas mix- Y ing means or blowpipe 22, enters the high pres- 4 heating mixture for both series of flames and jets is provided from a single blowpipe or gas mixer. Y

In the welding head illustrated in Fig. 3, both series ofames or jetsare again provided by a single unitary multi-flame welding head, but the gaseous heating mixture for each series of llames or jets is provided from a separate'blowpipe or gas mixing device. g t

Referring more particularly to Fig. 3, the unitary multi-name welding head comprises a shell IU drilled longitudinally to form passages 50 and 52. The right hand end of passage 50, as viewed in the drawing, is counterbored, forming a shoulder 64, and the right hand end of passage 52 is similarly 'counterbored, forming a shoulder 66. A xed baille 58, secured against shoulder 64, divides passage 50 into a preheating gas inlet section 60 and a welding gas inlet section 62. Simi- -preheating gas discharge ports or orifices 24, comsure section 40 of chamber I2 through the inlet -portion 20. From sectionl 40, thegaseous heating mixture, which is under relatively high pressure, passes into chamber I4 through drillings `46,*and is discharged from the preheating' ports or orifices 24 at a. relatively high velocity. l

Because of the relatively high pressure existing in section l4I) of chamber I2, some of the gaseous heating mixture will pass through the pressure reducing means 36 into the section 42 of the inlet chamber I2. This mixture will pass through the drilling 48 into outlet chamber I6 from which it will be` discharged through the, welding flame ports or discharge oriiices 2 6. Because of its passage through the restricting orice 36, the velocity of'the gaseous heating mixture discharged from ports 26 will be much lower than the velocity of the preheating ames. Theproper -rato of the two velocities. may beobtainedby varying the y sizeof the pressure reducing orifice 36, as 'by removing the one shown and substituting one of a different size. If desired,the shell I0 may be water-cooled toprevent overheating.

It will be 'noted that in this embodiment of the invention, a series of high velocity preheating flames or jets and a-series'of low velocity welding flames or jets are supplied from a single unitary multi-flame welding head; and that the gaseous larly, a iixcdbaille 64 seated against shoulder 56, divides passage 62 intooutlet chambers 66 and 68. The outer ends of'sections 68 and 62 are closed by iixed plugs 'I0 and 12, respectively, and the outer ends of chambers 66 and 68 are closed by fixed plugs 'I4 and 16, respectively.

'Threaded inlet'portions 'i8 and 80 are formed in the upper wall of each chamber and 62 for receiving the ends of blowpipes or gas mixing means 82 and 84, respectively. The lower wall of chamber 66 is formed with a series of preheating gas discharge ports or orifices 86, and the -lower Wall of chamber 68 is formed with a series of welding gas discharge ports or orifices 88. Lateral drillings 90 and 92 provide communication between chambers (illand 66 and between chambers 62 and 68, respectively.

With this embodiment of the invention, the relative velocities of the preheat flames or jets and the welding names o r jets may be independently regulated lby suitable adjustments of the blowpipes 82 and 84.

When the unitary multi-flame fusion welding head of the invention is employed for pipe and tube welding, as illustrated in Fig. 1, it is so disposed 'thatthe series of preheating and welding ports or discharge orices are. aligned longituwelding flames P progressively melt the vmetal of the edges. and, as the formed skelp passes through the closing die or closing pressure rolls, a strong weld of uniform high quality is produced. l

The combining of the preheating and welding apparatus in a single unitary Welding head increases the simplicity of welding and results in a considerable economy of space without detracting from the quality of the weld.

It should be understood that thel invention may be variously embodied otherwise than as shown and described without departing from the principles of the invention and within the scope of the appended claims.

. Certain features of the `present invention are claimed in application Serial No. 458,627, flled aiutarev September 17,' 1942, which is, in part, a continnation ofthe present application.

Whatisclaimed is:

1. A unitary multi-flame welding head with an inlet chamber, a pair oi.' outlet chambers. and gas discharge oriiices communicating with each of said outlet chambers; pressure reformed v ducing means secured in said inlet chamber and l dividing the saineinto two sections; and means establishing communication between each of such sections and an outlet chamber. l

' 2.' A unitary multi-flame welding headfiormed with an inlet chamber, a pair oi outlet chamhere, preheating sas discharge orifices communicating with one of said oulet chambers, and. welding gas orifices communicatingwith the other of said outlet chambers; pressurereduoing w .il dividing said inlet chamber intoiirst and second sections; means for supplying a gaseous heating mixture to said irst section: and means establisg communication between said ilrst section said onejoutlet chamber, and -between saidsecond section and said other outlet @n i tr, respectively.

, t. Apparatus for progressively preheatingand welding a seam while the work is in continuous movement in the direction' of the seam, comprisil a head having a series of relatively high ve'- locity work preheating gas discharge .ports and a series of relatively ,low velocity'seam welding discharge ports, all oi said ports being low velocity welding llames. separatelongit -posed series 'oi parallel high velocity work prelleed for successively directing upon the @dees ci the `-work to be welded a series of e 'high velocity preheat dames .and a series oi aligned welding and .preheatingf 'as outlet chambers and 'communicating longitul. dinally aligned welding and preheating gas inlet chamber sections, the longitudinal 'axis oi' the head of theapparatus defined in claim 3, separate gas mixers for supplying diiierent gaseous heating mixtures to the'gas inlet' locity work preheating gas discharge ports and a series oi relatively low velocity seam welding sas discharge ports, all of said ports being arranged ior successively directing upon theedges oi the lwork tobe welded 'a series of high velocity preheat llames an'd a series of 1ow-velocity weld-- ing ilames, a pair oi separate longitudinually -aligned welding and preheating gas outlet chambers and a pair of longitudinally aligned heating and preheating gas inlet chamber sections, the 1ongltudinal axis oi said gasinlet chamber sections being parallel to that of said gas outlet chambers,

Aand the length of said welding gas chamber and section being less than that of said preheat gas chamber and section, one of said gas inlet chamber sections having a gas inlet, and a gas outlet communicating with the other gas inlet cham-"be section.

5. Apparatus for progressively preheating and welding a seam while the work is in continuous `movement in nthe direction of the seam, comi prising a multi-llame head comprising a shell having aligned high and low pressure gas outlet .chambers separated by a partition; the bottom' wall of said shell having a longitudinally disheating gas. discharge ports communicating with said pressure gas outlet chamberI and a se""\- ries otparaliellow velocity seam w lding gas rts-jcommunicating' with said low tlet chamber; said shell having reheating gas inlet chamber Qpressure welding gas inlet aligned with each other and parallel'frelation to and above said spectively. Y for supplying preheating high-'pressureand lwelding' sas at low respectively, to said sections.

chamber sections. v v

" 'L'Apparatus as deiined by claim 5including separate blowpipe means ior supplying cases at different 

